Engineers and technicians work together to install reaction wheels on the underside of the main body of NASA's Europa Clipper spacecraft. The integration of the wheels was one of the latest steps of the spacecraft's assembly, test, and launch operations phase, now underway way in the Spacecraft Assembly Facility at the agency's Jet Propulsion Laboratory in Southern California. Europa Clipper is set to launch to Jupiter's moon Europa in October 2024.

When the spacecraft heads through deep space, slips into orbit around Jupiter, and collects science observations while flying dozens of times by Europa, the wheels rotate the orbiter so that its antennas can communicate with Earth and so its science instruments, including cameras, can stay oriented toward Europa. Two feet wide and made of steel, aluminum, and titanium, the wheels spin rapidly to create a force that causes the orbiter to rotate in the opposite direction. The wheels will run on electricity provided by the spacecraft's vast solar arrays.

Scientists believe the icy moon Europa harbors a vast internal ocean that may have conditions suitable for supporting life. Europa Clipper will fly by the moon about 50 times while its suite of science instruments gathers data on the moon's atmosphere, surface, and interior – information that will help scientists learn more about the ocean, the ice crust, and potential plumes that may be venting subsurface water into space.

For more information about Europa and Europa Clipper, go to: europa.nasa.gov